Efficacy of combined formulation of bromadiolone and cholecalciferol in reducing rodent population and damage in agricultural crop fields

Abstract Background Field rodents cause significant damage to standing crops in agroecosystems at vulnerable stages. Of all the methods available, chemical rodent control is the most practical and economically feasible. Laboratory studies demonstrate the potential of synergistic bait formulations containing bromadiolone and cholecalciferol. This study is the first multi-site multi-crop trial to assess the efficacy of cereal bait formulations containing lower than standard doses of bromadiolone (0.0025 and 0.001%) and cholecalciferol (0.02 and 0.04%) compared to presently recommended bait formulations of zinc phosphide (2.0%) and bromadiolone (0.005%) to protect wheat, rice and sugarcane crop fields against rodent attack. Results Rodent control success was highest (74.21–88.80%) in fields treated with a combination bait formulation containing bromadiolone (0.0025%) and cholecalciferol (0.04%), which led to a significant reduction in crop damage (from 6.82 to 26.56% cut tillers/canes and 251.75–1448.00 kg/ha yield loss (in reference block) to 1.18–6.18% cut tillers/canes and 46.67–745.00 kg/ha yield loss (in treated blocks). Conclusions This study therefore found that cereal bait formulation containing bromadiolone (0.0025%) and cholecalciferol (0.04%) can be effectively used to manage rodent population in agricultural crop fields and it is suggested that consideration be given to registering this combination rodenticide formulation to improve global food security.